Tourist submarine missing!

[stevensfo]

Five people inside a small submarine capable of going down to 4km depth to visit the Titanic.

https://uk.news.yahoo.com/titanic-subma ... 40213.html

I truly hope they're found soon before the air runs out.

But this caught my attention:

While the hopes are that the vessel has reached the surface, as it will be easier for rescue crews to spot, this would not help the trapped passengers unless they are discovered - as the submersible is bolted from the outside.

Former passenger David Pogue told the BBC: "There's no way to escape, even if you rise to the surface by yourself. You cannot get out of the sub without a crew on the outside letting you out."

This seems totally crazy to me, though maybe there's a very good reason. Anyone know why it's been designed in this way?

Steve

[ReformedCharacter]

A journalist invited on to Titanic journey last year noted the vessel's construction seemed curiously 'off-the-shelf' ...It was the opportunity of a lifetime. A chance to plumb the depths of the Atlantic Ocean, and view the haunting wreck of the Titanic. But David Pogue, a journalist for US broadcaster CBS, had some misgivings about his prize assignment as he climbed aboard last summer. If the mission was grand, “Titan” the submersible ferrying passengers almost two-and-a-half miles below the ocean, was anything but. No roomier than a minivan, it was, incredibly, piloted by a video game controller; its lighting purchased from a camping shop, construction pipes making do as ballast. “I couldn’t help noticing how many pieces of this sub seemed improvised, with off-the-shelf components,”

https://www.telegraph.co.uk/world-news/2023/06/19/titanic-oceangate-submersible-missing-in-atlantic-recon/

RC

[Tedx]

Five people inside a small submarine capable of going down to 4km depth to visit the Titanic.

https://uk.news.yahoo.com/titanic-subma ... 40213.html

I truly hope they're found soon before the air runs out.

But this caught my attention:

While the hopes are that the vessel has reached the surface, as it will be easier for rescue crews to spot, this would not help the trapped passengers unless they are discovered - as the submersible is bolted from the outside.

Former passenger David Pogue told the BBC: "There's no way to escape, even if you rise to the surface by yourself. You cannot get out of the sub without a crew on the outside letting you out."

This seems totally crazy to me, though maybe there's a very good reason. Anyone know why it's been designed in this way?

Steve

You would think there would be a wee hammer in a box on the wall somewhere with a 'In case of emergencies break glass'

[bungeejumper]

So it's lost contact, 12,000 feet down, and it doesn't have a working transponder and it won't deliver on sonar or radio or GPS because those things don't work under that much water. Yes, I get that much.

But if I were going down that deep, with an accompanying vessel remaining on the surface, I think I'd have invested in a communications wire, or a bit of string or something, so that they'd know roughly where I was.

Horrible business, though. The fact that the dive company's chief exec was in the sub suggests to me that they were going to try and push the boundaries somehow. I hope they'll all be all right, but it doesn't look great.

BJ

[Dod101]

It is not of course our ordinary tourist. They are paying apparently US$250,000 each for the privilege which strikes me as being one of the more stupid and I suppose selfish ways to spend money.

Dod

[Tedx]

So it's lost contact, 12,000 feet down, and it doesn't have a working transponder and it won't deliver on sonar or radio or GPS because those things don't work under that much water. Yes, I get that much.

But if I were going down that deep, with an accompanying vessel remaining on the surface, I think I'd have invested in a communications wire, or a bit of string or something, so that they'd know roughly where I was.

Horrible business, though. The fact that the dive company's chief exec was in the sub suggests to me that they were going to try and push the boundaries somehow. I hope they'll all be all right, but it doesn't look great.

BJ

...or they could be bobbing about on the surface somewhere, waiting to be rescued - which is probably just as bad if they're found in a fortnight.

[bungeejumper]

...or they could be bobbing about on the surface somewhere, waiting to be rescued - which is probably just as bad if they're found in a fortnight.

Aye, but GPS and suchlike would work on the surface, and then they be sorted within a few hours. There are quite a lot of things about this situation that mystify me.

BJ

[stevensfo]

So it's lost contact, 12,000 feet down, and it doesn't have a working transponder and it won't deliver on sonar or radio or GPS because those things don't work under that much water. Yes, I get that much.

But if I were going down that deep, with an accompanying vessel remaining on the surface, I think I'd have invested in a communications wire, or a bit of string or something, so that they'd know roughly where I was.

Horrible business, though. The fact that the dive company's chief exec was in the sub suggests to me that they were going to try and push the boundaries somehow. I hope they'll all be all right, but it doesn't look great.

BJ

Yes, that was my thought as well. It surely can't be that difficult to have a strong/thin 4000 metre cable attached between the submersible and ship on the surface.

They were laying thick cables across the Atlantic well over a hundred years ago, and I think technology has improved since then.

I will refrain from any frivolous comments. Being claustrophobic myself, I can imagine how I would feel, and just pray for their safe return.

Steve

[Itsallaguess]

There are quite a lot of things about this situation that mystify me.

A Telegraph article discussing the build of the submersible talks about it having 'seven different ways to rise to the surface', one of which has been mentioned elsewhere on the news as being the ability to mechanically release ballast, which should then float them to the surface if they get into trouble.

How OceanGate built 'improvised' submersible from camping kit and a video game controller -

https://www.telegraph.co.uk/world-news/2023/06/19/titanic-oceangate-submersible-missing-in-atlantic-recon/

Given that situation then, with multi-layered surfacing processes, it seems that there's really only three scenarios -

• They're on the surface now and need to get found and opened up before their oxygen runs out.

• They've had a catastrophic event regarding hull integrity, with little chance of survival at the type of depths they were due to spend quite some time at.

• They're snagged on something at depth, and none of the normal emergency-surfacing processes are designed to cope with major snags.

This must be a terrible time for families and friends, as well as the large numbers involved in the current rescue efforts, and I hope for a good outcome.

Cheers,

Itsallaguess

[monabri]

So it's lost contact, 12,000 feet down, and it doesn't have a working transponder and it won't deliver on sonar or radio or GPS because those things don't work under that much water. Yes, I get that much.

But if I were going down that deep, with an accompanying vessel remaining on the surface, I think I'd have invested in a communications wire, or a bit of string or something, so that they'd know roughly where I was.

Horrible business, though. The fact that the dive company's chief exec was in the sub suggests to me that they were going to try and push the boundaries somehow. I hope they'll all be all right, but it doesn't look great.

BJ

Discussed this morning on BBC5 live. The experts (former submariners) comment

- the drag from a cable to the surface would mean the sub needed very large engines to overcome
-the cable would restrict where the sub could go ( fear of entanglement)
- there are subs with such cables but they are unmanned rescue/exploratory ones

[Tedx]

Wire guided torpedos are commonplace and the wire can be as much as 26km in length

Guidance Wire For TorpedoesThe guidance wire acts as a medium for communication of data between the torpedo and the firing platform (ship or a submarine}. The wire is also a medium for communicating data for the guidance of the torpedo towards target during its underwater run.

DRDO has developed guidance wire spools for wire-guided torpedoes. The guidance wire of 26 km length has been divided into two spools of different lengths. Each spool has a two-core copper cable, wound with a special criss-cross winding technique for free unreeling of the cable during the underwater run of the torpedo.The entire length of the cable is free from pin holes. The two spools are interconnected by an underwater connector and can withstand a pressure of40 bar.

This system has undergone sea trials and performed satisfactorily. The system can be used for all future wire guided torpedoes having copper cable as medium of communication.

https://www.drdo.gov.in/guidance-wire-torpedoes

[simsqu]

Terrible nail-biting ongoing story for the six occupants and their relatives, (can you sense a but coming?), but I wonder if there would have been so much intense media interest and monetary expenditure on the search effort if the occupants had been 6 fleeing refugees rather than billionaires?

OK, not very likely, but I am thinking of the massive loss of life in the hundreds, on the migrant ship lost in the Med, which already seems to be receding from the headlines.

[XFool]

You would think there would be a wee hammer in a box on the wall somewhere with a 'In case of emergencies break glass'

I'd like to see you try that, with glass designed to stand the pressure under 12,600 feet of water.

[XFool]

But this caught my attention:

While the hopes are that the vessel has reached the surface, as it will be easier for rescue crews to spot, this would not help the trapped passengers unless they are discovered - as the submersible is bolted from the outside.

Former passenger David Pogue told the BBC: "There's no way to escape, even if you rise to the surface by yourself. You cannot get out of the sub without a crew on the outside letting you out."

This seems totally crazy to me, though maybe there's a very good reason. Anyone know why it's been designed in this way?

I don't really know but suspect this is the way all such craft intended to go to these depths are designed. The 'hatch' is bolted in place, using a non small number of bolts, from the outside - where the pressure will be coming from. You can't expect a simple locking hatch on such a vessel.

[XFool]

So it's lost contact, 12,000 feet down, and it doesn't have a working transponder and it won't deliver on sonar or radio or GPS because those things don't work under that much water. Yes, I get that much.

Sonar certainly works underwater. It is the main underwater communication/detection system of both men and sea creatures. 'Sound' travels much better in mediums denser than air.

But why don't they have an emergency sonar beacon?

But if I were going down that deep, with an accompanying vessel remaining on the surface, I think I'd have invested in a communications wire, or a bit of string or something, so that they'd know roughly where I was.

I understand from reports that they could communicate with the surface vessel via "text messages". Presumably using acoustic communication? Or even an optical link, but that would surely only work at shallow depths?

[WrenChasen]

It's reported passengers are required to sign a waiver acknowledging the submarine isn't approved by any regulatory body...which would have been a big red flag for me.

[bungeejumper]

Sonar certainly works underwater. It is the main underwater communication/detection system of both men and sea creatures. 'Sound' travels much better in mediums denser than air.

Mr Google says that 2,400 metres is about as deep as sonar will functionally go. I'm no scientist, and I certainly don't understand the differences between sonar types, but I would be interested to hear if that's wrong?

But why don't they have an emergency sonar beacon?

Good question. Even if it only works at relatively shallow depths!

BJ

[BullDog]

One astonishing thing I read was the submarine is built from carbon fibre and titanium, very cutting edge. It carries no official certification of independent verification. Nor any insurance company coverage. If that's true, I'd love to see the disclaimer that passengers sign when handing over their $250,000. It's either just a few words or many pages of legalese. But it means you get aboard knowing there's a possibility you won't return alive. If at all.

[XFool]

Titan

Ocean Gate

5-Person Submersible | 4,000 Meters

You can see that the bolt on hatch (I count 16 bolts) and the viewport are the same thing.

[Lanark]

Catastrophic implosion seems the most likely explanation the vessel has done this trip 6 or so times last year possibly building up stress fractures in the titanium/carbon fibre hull and this was the first trip after being stored all winter.